I think the problem isn’t mistakes in the methodology, nor is it utilitarianism in general, but one specific feature of DALYs: it is multiplicative instead of additive.
Since DALYs is the years of life lost times the disease burden (where the disability burden is a scalar determined by surveys), the marginal utility of a disabled persons years of life is multipled by the disability burden.
If instead you had a unit that was years of life lost minus disease burden (where the disability burden is a number of years that can determined by same surveys), the marginal utility of a disabled person’s years of life and a healthy person’s years of life is the same!
So the problem isn’t trying to price every intervention in utils, it’s that DALYs specifically are an incorrect way to weigh years of life v.s. disease burden.
One advantage of multiplying is it shows it is helpful to cure diseases earlier, because the benefit is multiplied by the number of years of life remaining.
If you instead subtracted, it seems like we would have little reason not to delay treatment—because curing a 1yo and a 50yo of blindness would both count for the same number of years, implicitly valuing 49 years of sight at zero.
Can you clarify why you think it’s “incorrect” to conceive of disease burden as ongoing, or applying per unit of time, and more accurate to treat it as a per-life constant?
One objection to the “per-life constant” approach is that it could easily incorrectly imply that some short-lived but happy disabled lives are net-negative for the person living it. (Suppose the constant burden for deafness comes out to one year per lifetime, and then imagine a deaf child who lives happily for less than one year. So long as their short life was happy, it would seem inaccurate to call it net-negative! By contrast, the standard per-unit-of-time approach allows that happy deaf lives are always worth living, just not quite as good as they would have been without the mild disability.)
I think the problem isn’t mistakes in the methodology, nor is it utilitarianism in general, but one specific feature of DALYs: it is multiplicative instead of additive.
Since DALYs is the years of life lost times the disease burden (where the disability burden is a scalar determined by surveys), the marginal utility of a disabled persons years of life is multipled by the disability burden.
If instead you had a unit that was years of life lost minus disease burden (where the disability burden is a number of years that can determined by same surveys), the marginal utility of a disabled person’s years of life and a healthy person’s years of life is the same!
So the problem isn’t trying to price every intervention in utils, it’s that DALYs specifically are an incorrect way to weigh years of life v.s. disease burden.
One advantage of multiplying is it shows it is helpful to cure diseases earlier, because the benefit is multiplied by the number of years of life remaining.
If you instead subtracted, it seems like we would have little reason not to delay treatment—because curing a 1yo and a 50yo of blindness would both count for the same number of years, implicitly valuing 49 years of sight at zero.
Can you clarify why you think it’s “incorrect” to conceive of disease burden as ongoing, or applying per unit of time, and more accurate to treat it as a per-life constant?
One objection to the “per-life constant” approach is that it could easily incorrectly imply that some short-lived but happy disabled lives are net-negative for the person living it. (Suppose the constant burden for deafness comes out to one year per lifetime, and then imagine a deaf child who lives happily for less than one year. So long as their short life was happy, it would seem inaccurate to call it net-negative! By contrast, the standard per-unit-of-time approach allows that happy deaf lives are always worth living, just not quite as good as they would have been without the mild disability.)